Zoledronate Slows Weight Loss and Maintains Fat Mass in Osteopenic Older Women: Secondary Analysis of a Randomized Controlled Trial

Energy homeostasis in the bone

The bone serves as an energy reservoir and actively engages in whole-body energy metabolism. Numerous studies have determined fuel requirements and bioenergetic properties of bone under physiological conditions as well as the dysregulation of energy metabolism associated with bone metabolic diseases. Here, we review the main sources of energy in bone cells and their regulation, as well as the endocrine role of the bone in systemic energy homeostasis. Moreover, we discuss metabolic changes that occur as a result of osteoporosis. Exploration in this area will contribute to an enhanced comprehension of bone energy metabolism, presenting novel possibilities to address metabolic diseases.

Zoledronate Reduces Height Loss Independently of Vertebral Fracture Occurrence in a Randomized Trial in Osteopenic Older Women

Vertebral fractures are associated with height loss, reduced quality of life, and increased mortality and are an important endpoint for osteoporosis trials. However, height loss is associated with quality of life and mortality independent of associations with fracture. We have used data from a recent 6-year trial of zoledronate in 2000 osteopenic women aged >65 years to assess the impact of the semiquantitative and quantitative components of the definition of vertebral fracture on the outcome of that trial, to determine what factors impacted on height loss and to test whether height loss can be used as a surrogate for vertebral fracture incidence. In the trial protocol, an incident vertebral fracture was defined as a change in Genant grade plus both a 20% and 4 mm decrease in a vertebral height. The addition of the quantitative criteria reduced the number of fractures detected but did not change the size of the anti-fracture effect (odds ratios of 0.49 versus 0.45) nor the width of the confidence intervals for the odds ratios. Multivariate analysis of baseline predictors of height change showed that age accelerated height loss (p < 0.0001) and zoledronate reduced it (p = 0.0001). Incident vertebral fracture increased height loss (p = 0.0005) but accounted for only 0.7% of the variance in height change, so fracture could not be reliably inferred from height loss. In women without incident vertebral fractures, height loss was still reduced by zoledronate (height change: zoledronate, -1.23; placebo -1.51 mm/yr, p < 0.0001). This likely indicates that zoledronate prevents a subtle but widespread loss of vertebral body heights not detected by vertebral morphometry. Because height loss is associated with quality of life and mortality independent of associations with fracture, it is possible that zoledronate impacts on these endpoints via its effects on vertebral body integrity. © 2022 American Society for Bone and Mineral Research (ASBMR).

Anti-osteoporosis treatments changed body composition in postmenopausal women: A systematic review and meta-analysis

BACKGROUND

Whether the widespread anti-osteoporosis treatments in postmenopausal women also benefit the change of body composition (lean body mass [LBM] and body fat mass [FM]) remains controversial. In order to solve this issue and find out the most effective treatment, we conducted this meta-analysis.

METHODS

We searched the literature, via PubMed, Embase, Scopus, Web of Science, and Cochrane to screen citations from inception to March 26, 2022, for inclusion in this study. Only clinical trials that used anti-osteoporosis treatments in postmenopausal women and displayed the alteration of body composition were included. Stata 14.0 was used for the meta-analysis.

RESULTS

Our meta-analysis results presented that: compared with placebo, hormone replacement therapy (HRT) was associated with increased LBM (standardized mean differences [SMD] = 0.32, 95% confidence interval [CI] = 0.02-0.61) and reduced FM (SMD = -0.30, 95% CI = -0.51 to -0.09) in postmenopausal women. Compared with placebo, physical exercise training showed an effect of decreasing FM (SMD = -0.66, 95% CI = -0.94 to -0.38) but not significant influence LBM (SMD = 1.31, 95% CI = -0.29 to 2.91). The network meta-analysis of our study showed that oral estrogen and progestogen plus exercise (OEPE) treatment might be the most effective anti-osteoporosis treatment (surface under the cumulative ranking curve 99.9) to reduce FM in postmenopausal women.

CONCLUSIONS

anti-osteoporosis treatments, especially HRT, affect body composition. Furthermore, the combination of HRT and exercise training are the most effective treatment to reduce FM while maintaining LBM.

The effects of metformin and alendronate in attenuating bone loss and improving glucose metabolism in diabetes mellitus mice

Background: To explore the anti-osteoporosis and anti-diabetes effects and potential underlying mechanisms of treatment with metformin and alendronate in diabetes mellitus mice.

Methods: Eight-week-old C57 BL/KS db/db and db/+ female mice were evaluated according to the following treatment group for 12 weeks: control group, diabetes mellitus group, diabetes mellitus with metformin group, diabetes mellitus with Alendronate group, diabetes mellitus with metformin plus alendronate group. Glucose level, glucose tolerance test, bone mineral density, bone microarchitecture, bone histomorphometry, serum biomarkers, and qPCR analysis.

Results: Combined metformin and alendronate can improve progression in glucose metabolism and bone metabolism, including blood glucose levels, blood glucose levels after 4 and 16 hours fasting, glucose tolerance test results, insulin sensitivity and reduces bone loss than the diabetes group. The use of alendronate alone can increase significantly serum glucagon-like peptide-1 levels than the diabetes group. The use of metformin alone can improve bone microstructure such as Tb.Sp and Tb.N of spine in diabetic mice.

Conclusion: The combined use of alendronate and metformin has an anti-diabetes and anti-osteoporotic effect compared with diabetic mice, but they appear to act no obvious synergistically between alendronate and metformin.

Zoledronic acid does not affect insulin resistance in men receiving androgen deprivation therapy: a prespecified secondary analysis of a randomised controlled trial

BACKGROUND

Animal studies suggest that undercarboxylated osteocalcin may improve insulin sensitivity via its effect on testicular testosterone production. Human studies have been conflicting. Men undergoing androgen deprivation therapy (ADT) for prostate cancer experience profound hypogonadism resulting in increased insulin resistance. In a randomised controlled trial (RCT) of zoledronic acid versus placebo in men commencing extended-duration ADT, we aimed to examine the effects on fat mass and glucose metabolism. We hypothesised that zoledronic acid, which reduces osteocalcin concentrations, would worsen ADT-induced insulin resistance.

METHODS

This was a prespecified secondary analysis of an RCT designed to evaluate the effects of zoledronic acid on bone microarchitecture in 76 men with non-metastatic prostate cancer undergoing curative radiotherapy combined with adjuvant ADT (n = 39 randomised to a single dose of zoledronic acid 5 mg, n = 37 randomised to matching placebo). Oral glucose tolerance tests to determine Matsuda Index were performed at 0, 3, 12 and 24 months. Using a mixed model, mean adjusted differences [MAD (95% confidence interval)] between the groups over time are reported.

RESULTS

Over 24 months of ADT, fat mass increased and lean mass decreased for both groups, with no significant between group difference [MAD 401 g (-1307; 2103), p = 0.23 and -184 g (-1325; 955), p = 0.36 respectively]. Bone remodelling markers C-telopeptide [MAD -176 ng/l (-275; -76), p < 0.001 and P1NP -18 mg/l (-32; -5), p < 0.001] as a surrogate for osteocalcin, remained significantly lower in the zoledronic acid group, compared with placebo. There was no mean adjusted between-group difference for homeostatic model assessment 2 insulin resistance (HOMA2-IR) [-0.2 (-0.6; 0.2), p = 0.45], HbA1c [-0.1% (-0.3; 0.1), p = 0.64] or Matsuda Index [0.8 (-1.1; 2.7), p = 0.38]. The Matsuda Index decreased in both groups consistent with worsening insulin resistance with ADT.

CONCLUSION

A single dose of zoledronic acid does not appear to influence glucose metabolism in men newly commencing ADT. Further study to evaluate the endocrine relationship between bisphosphonates, bone and glucose metabolism is required.

TRIAL REGISTRATION NUMBER

[ClinicalTrials.gov identifier: NCT01006395].